Rapid climate fluctuations over the past millennium: evidence from a lacustrine record of Basomtso Lake, southeastern Tibetan Plateau.

Li K, Liu X, Herzschuh U, Wang Y - Sci Rep (2016)

Bottom Line:
At the centennial time scale, the Medieval Climate Anomaly (MCA), Little Ice Age (LIA) and Current Warm Period (CWP) are distinct in the Basomtso region.These episodes with higher and lower sediment input are characterized by abrupt climate changes and short time durations.Spectral analysis indicates that the climate variations at the centennial scale on the southeastern Tibetan Plateau are influenced by solar activity during the past millennium.

ABSTRACTAbrupt climate changes and fluctuations over short time scales are superimposed on long-term climate changes. Understanding rapid climate fluctuations at the decadal time scale over the past millennium will enhance our understanding of patterns of climate variability and aid in forecasting climate changes in the future. In this study, climate changes on the southeastern Tibetan Plateau over the past millennium were determined from a 4.82-m-long sediment core from Basomtso Lake. At the centennial time scale, the Medieval Climate Anomaly (MCA), Little Ice Age (LIA) and Current Warm Period (CWP) are distinct in the Basomtso region. Rapid climate fluctuations inferred from five episodes with higher sediment input and likely warmer conditions, as well as seven episodes with lower sediment input and likely colder conditions, were well preserved in our record. These episodes with higher and lower sediment input are characterized by abrupt climate changes and short time durations. Spectral analysis indicates that the climate variations at the centennial scale on the southeastern Tibetan Plateau are influenced by solar activity during the past millennium.

Mentions:
The loss on ignition (LOI) of BSCW-1 ranges from 1.0% to 5.5% with an average of 2.6% (Fig. 3). The LOI values were relatively high for sediments that accumulated within the period of the 1080s–1140s and were low for the period of the 1140s–1800s. The LOI values were relatively high for the sediments deposited after 1800s, with an average of 3.5%. The variations in total organic carbon (TOC) and total nitrogen (TN) generally paralleled that of the LOI; i.e., higher TOC and TN values correspond to higher LOI values (Fig. 3). However, some periods characterized by lower LOI values (labelled 1–7) and brief high LOI values (labelled I–V), as well as rapid increases in the LOI, were recorded between the 1140s and the 1800s (Fig. 3).

Mentions:
The loss on ignition (LOI) of BSCW-1 ranges from 1.0% to 5.5% with an average of 2.6% (Fig. 3). The LOI values were relatively high for sediments that accumulated within the period of the 1080s–1140s and were low for the period of the 1140s–1800s. The LOI values were relatively high for the sediments deposited after 1800s, with an average of 3.5%. The variations in total organic carbon (TOC) and total nitrogen (TN) generally paralleled that of the LOI; i.e., higher TOC and TN values correspond to higher LOI values (Fig. 3). However, some periods characterized by lower LOI values (labelled 1–7) and brief high LOI values (labelled I–V), as well as rapid increases in the LOI, were recorded between the 1140s and the 1800s (Fig. 3).

Bottom Line:
At the centennial time scale, the Medieval Climate Anomaly (MCA), Little Ice Age (LIA) and Current Warm Period (CWP) are distinct in the Basomtso region.These episodes with higher and lower sediment input are characterized by abrupt climate changes and short time durations.Spectral analysis indicates that the climate variations at the centennial scale on the southeastern Tibetan Plateau are influenced by solar activity during the past millennium.

ABSTRACTAbrupt climate changes and fluctuations over short time scales are superimposed on long-term climate changes. Understanding rapid climate fluctuations at the decadal time scale over the past millennium will enhance our understanding of patterns of climate variability and aid in forecasting climate changes in the future. In this study, climate changes on the southeastern Tibetan Plateau over the past millennium were determined from a 4.82-m-long sediment core from Basomtso Lake. At the centennial time scale, the Medieval Climate Anomaly (MCA), Little Ice Age (LIA) and Current Warm Period (CWP) are distinct in the Basomtso region. Rapid climate fluctuations inferred from five episodes with higher sediment input and likely warmer conditions, as well as seven episodes with lower sediment input and likely colder conditions, were well preserved in our record. These episodes with higher and lower sediment input are characterized by abrupt climate changes and short time durations. Spectral analysis indicates that the climate variations at the centennial scale on the southeastern Tibetan Plateau are influenced by solar activity during the past millennium.